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Патент USA US3066469

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Dec- 4, 1962
Filed Sept. 16, 1960
5 Sheets-Sheet l
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DeC- 4, 1962
H. F. cooowm ET AL
Filed Sept. 16, 1960
3 Sheets-Sheet 5
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United States Patent O?ice
Filed Sept. 16, 196i), Ser. No. 56,476
2 Claims. (Cl. ‘SS-d4)
This invention relates to a method and mechanism for
practicing the same, both useful in packaging commodi
ties in a sealed enclosing wrapping.
While not limited to such use the invention ?nds par
Patented Dec. 4, 1%52
Harlan F. Goodwin, Nashua, Ronald S. Lahounty, Mil
ford, and Alfred L. Lysih, Hollis, N.H., assignors to
Nashua Corporation, Nashua, N.l-I., a corporation of
ping ?lm, ineffective activation of the end label and imper
fect sealing resulted.
In accordance with the present invention serious dam
age to wrapping ?lms which soften ‘at comparatively low
temperatures is avoided because they are not handled by
direct physical contact with metal or other parts during
the sealing operation, while activation of the adhesive is
effected by heat developed within the adhesive joint by the
absorption of radiant heat, preferably in the infra-red
10 range.
Referring now to FIGS. 1, 2 and 3 of the drawings,
there is there disclosed in a somewhat diagrammatic and
schematic manner a portion of a bread wrapping machine
at that paint in its length where the ends of the wrapping
ticular application to the packaging of bread and also to
the packaging of commodities (including bread) in a
are sealed.
It will be clear that the method is not limited to use for
that particular purpose, nor the mechanism to one de
into pleats and folded down by folding plates and tucking
The portions which are broken away at the
right and left of the ?gure may be of well known and con
ventional construction and do not require illustration or
wrapping ?lm of thin thermoplastic material such, for
description here. Referring to the drawings, a loaf of
example, as polyethylene and polypropylene. It will be
bread which at an earlier point has been wrapped around
convenient therefore in order to promote a ready compre
hension of the subject matter to describe the invention as 20 its smaller girth with a sheet of wrapping material such
utilized for wrapping a loaf of bread with such ?lm and
as polyethylene ?lm with projecting ends, is advanced over
to illustrate it in the accompanying drawings by the show
a table Ill by a pusher bar 12 depending from an overly
ing of a mechanism speci?cally adapted to such purpose.
ing conveyor lid, and these projecting ends are formed
signed for that particular application.
mechanism, portions of which are shown at the locations
16, 17, 13. As the bread passes these the wrapper is com
With this in mind the invention will be well understood
by reference to the following description taken in connec
pletely formed about it and the ends folded in and ready
tion with the accompanying drawings wherein:
FIG. 1 is a fragmentary plan view of a portion of a
bread wrapping machine having embodied in it a sealing
mechanism exemplifying the invention. The loaf advanc
ing mechanism is omitted;
FIG. 2 is a central vertical section showing in eleva
tion the same parts at one side of the machine and in
cludes the loaf advancing mechanism;
FIG. 3 is a perspective view of what appears in FIG. 2;
FIG. 4 is a view on a larger scale and in front elevation
of the sealing unit exemplifying the invention, the point
of view being the same as in FIG. 2; and
FIG. 5 is a section on the line 5——5 of FIG. 4.
The larger proportion of commercially baked bread in
the United States is sold wrapped. For many years the
wrapping was almost always waxed paper (which still is
used). A blank was wrapped around the shorter circum
ference of the bread and its ends folded in as overlapping
?aps at each end of the loaf. For many years past an
“end label” has generally been applied to these flaps and
adhered thereto to hold the ?aps and to seal the wrapping.
for sealing, as seen at the right in FIG. 3.
The end labels are supplied from rolls 2d at either side
of the machine. The strip leads through a dispensing
mechanism 22 and single labels are cut oif by knife 2-4.1,
FIG. 3, opposite the end of the loaf and pressed lightly
thereagainst by a suitable plunger 26 over which the loaf
and the still unattached label slide toward the left in FIGE.
35 1, 2 and 3, to be acted on by the mechanism more particu
larly involved in the present invention and exemplifying
the novel method of eiiecting the adhesive bond.
The details of the mechanism are shown on a relatively
large scale in FIGS. 4 and 5 . As the loaf with its unsealed
40 wrapper moves away from the place where the end labels
are presented to the ends thereof it comes under the in
tluence of two horizontal sheets of air blown inwardly
from upper and lower perforated pipes 28‘ spaced verti
cally at a distance less than the height of the label, which
blow against the label and the end of the loaf and hold
the former pressed against the latter as the loaf continues
its travel. While still under the influence of these sheets
of air radiant heat is applied to heat the label and activate
its adhesive coating and there is here shown a tier of three
This end label usually was a label in that it had an inscrip— 50 elongated tubular infra-red lamps Ell received in an open
tion on its outer surface, but it functioned as a sealing
topped box 32, the bottom of which is formed as a re_
sheet and the word “label" is used in that sense in this
flector. A portion of a protective screen over the open
front of the box is shown broken away in FIG. 4. The
A wax coating could be softened by heat and a reason
radiant energy from these lamps where it falls on the trans
ably satisfactory seal made, and various heat activatable
parent wrapping sheet proper passes through the same and
adhesisves (heat seal adhesives) have been developed for
is absorbed harmlessly into the loaf without developing
securing a label to a waxed wrapping. Direct contact of
a heated pressure plate was utilized to secure the label in
sheet, which is furthermore cooled by the air which
position. Wrappings with cellophane and end labels were
effected in a substantially similar manner. Relatively re—
cently thin, transparent ?lms of thermoplastic, such as
polyethylene, have become ‘available and in themselves
they make a desirable wrapping for a loaf of bread.
However, if it is attempted to handle them in the manner
suggested many di?iculties arise. Direct contact of these
?lms with a heated plate causes them to soften excessively
and the result is rupture, warping, loss of fit, and other
damage to the wrapper of the loaf. Moreover, the soft
ened ?lm had considerable adhesive qualities and would
any substantial heat to cause softening or distortion of the
streams over it after it encounters the end of the loaf. On
the contrary, in the location of the end label (36 at the
left on FIG. 3) the covering including the paper of the
label, the heat-sensitive adhesive layer on its inner face
and the multiple layers of the ?aps beneath the sam
folded inwardly are of such thickness and relative opacity
as to have a substantial heat absorbing capacity resulting
in ‘activation of the adhesive which grabs hold of the
underlying ?lm while the label is held immovably rela
stick to the metal plunger and other adjacent objects which
came in contact with it, causing breakage. If the sealing
tive to the wrapping and the loaf by the same columns of
pressure of the air. There is no contact of any heated
parts or indeed of any solid bodies with the end of the
wrapping or with the label at this time.
temperatures were lowered to avoid damage to the wrap
After adhesion is etfected in this way the ends of the
loaf with the adherent labels may, if desired, pass in con
tact with an idler drum
to iron out the area treated
and further to insure complete sealing.
The loaf may
move further in the machine to a location not illustrated,
and the area here may be a cooled environment to harden
or set the adhesive in the manner conventional in the case
of end labels as applied to wax paper or cellophane wrap
pers in the prior art.
It has been proposed hitherto to activate label-s having
1. The method of closing a wrapping of thin transpar
ent thermoplastic material. about articles which comprises
folding a sheet of such material about the article and
forming edge portions thereof into overlapping ?aps, ap
plying over the ?aps a relatively opaque joining member
of relatively high heat-absorbing capacity having a heat
seal coating, holding the joining member in position by a
current of air directed against its-uncoated face and se
curing cohesion of the ?aps and the overlying member by
a heat seal coating (preferably one of the two phase or 10 radiant heat projected externally/against the joint.
“delayed action” type ‘described in the Perry Patent
2,462,029) by radiant heat incident on the exposed face
of the adhesive after which the label was moved to and
2. Mechanism for enclosing a commodity in a sealed
wrapping comprising a support for receiving the commod
ity with unsealed wrapping material folded thereabout,
and thus is not claimed. The heat in the present case is
means for positioning over the portions to be sealed a
joining label having a heat-seal coating, means for main
generated internally of the temporary assembly of label
taining the label in position by projecting a current of air
and object and the ‘activation occurs in situ.
thereagainst and means for radiating heat from a remote
source on the so collocated parts to develop reciprocal
adhesiveness therein;
pressed against the object to which it was to be attached
We are aware that the invention may be embodied in
other speci?c forms without departing from the spirit or
essential attributes thereof, and we therefore desire the 4
present embodiment to be considered in ‘all respects as
illustrative and not restrictive, as is in fact clear in several
matters from the description itself. Reference is to be
had to the appended claims to indicate those prinicples of
the invention exempli?ed by the particular embodiment ~
described and which we desire to secure by Letters Patent.
We claim:
References Cited ‘in the ?leof this patent
Danquigney __________ __ Sept. 21, 1926
Smith _______________ _._ Nov. 21, 1933
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